Stroke and Cold Weather

“Our study shows a clear association between temperature and risk of ischemic stroke in patients with AF,” Chao said in a release issued by the European Society of Cardiology.

[www.lifezette.com]

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Along with colder weather, typically comes less sunshine exposure to bare skin and vitamin D deficiency as well; although, other studies show that many living in hot climates tend to avoid getting adequate sunshine exposure because of the heat and also test very low in vitamin D levels. Here's couple recently published:

LOW VITAMIN D LEVEL RELATED TO
STROKE LESION VOLUME AND OUTCOMES

Researchers reported in July 2015 that low
serum vitamin D levels correlated with larger
ischemic infarct volumes and poorer outcomes
with ischemic stroke. The Centers for Disease
Control and Prevention (CDC) states that
stroke kills approximately 130,000 Americans
per year. They estimate that 87% of all strokes
are ischemic strokes, which result from block-
age to an artery leading to the brain.

The subjects included 96 individuals with
magnetic resonance imaging (MRI)-proven
acute ischemic stroke. Investigators evaluated
the influence of serum 25-hydroxyvitamin D
levels on ischemic infarct volume and 90-day
post-stroke outcomes.

Lacunar strokes (small, subcortical ischemic
strokes), lowered the score on the National
Institutes of Health Stroke Scale at admission
(severity of stroke), and higher serum vitamin
D levels all correlated with smaller infarct
volume. Vitamin D was an independent risk
factor for infarct size. Furthermore, the resear-
chers determined that with each 10 ng/mL
drop in serum 25-hydroxyvitamin D, the risk
of an unfavorable outcome at 90 days doubled.

The study authors stated, “Low serum
25-hydroxyvitamin D was independently
associated with larger ischemic infarct volume,
which may partially explain observed worse
outcomes in ischemic stroke patients with poor
vitamin D status. Although causality remains
to be proven, our results provide the rationale
to further explore vitamin D as a promising
marker for cerebral ischemic vulnerability
and to identify stroke patients at high risk for
poor outcome.”

REFERENCE:
Turetsky A, et al. J Stroke Cerebrovasc Dis. 2015;24:1555-63


......and consider this recent study on stroke risk as well:

Am J Clin Nutr. 2015 Jun;101(6):1269-77. doi: 10.3945/ajcn.114.100354. Epub 2015 May 6.

Association between intakes of magnesium, potassium, and calcium and risk of stroke: 2 cohorts of US women and updated meta-analyses.

Adebamowo SN1, Spiegelman D2, Willett WC2, Rexrode KM2.


Erratum in
• Erratum for Adebamowo et al. Association between intakes of magnesium, potassium, and calcium and risk of stroke: 2 cohorts of US women and updated meta-analyses. Am J Clin Nutr 2015;101:1269-77. [Am J Clin Nutr. 2015]

Abstract

BACKGROUND:
Prospective data on the relation of magnesium, potassium, and calcium intakes with stroke risk are inconsistent, and to our knowledge, the effect of a combined mineral diet score has not been examined.

OBJECTIVE:
We examined associations between intakes of magnesium, potassium, and calcium and risk of incident stroke in 86,149 women in the Nurses' Health Study (NHS) I and 94,715 women in the NHS II.

DESIGN:
In this prospective cohort study, we calculated HRs of stroke by quintiles of intake for each mineral and for a combined diet score of all 3 minerals by using multivariate Cox proportional hazard models. In addition, we updated meta-analyses on dietary intakes of these minerals and risk of stroke.

RESULTS:
During follow-up (30 y in the NHS I; 22 y in the NHS II) a total of 3780 incident stroke cases were documented. Pooled multivariate RRs of total stroke for women in the highest compared with the lowest quintiles were 0.87 (95% CI: 0.78, 0.97) for total magnesium, 0.89 (95% CI: 0.80, 0.99) for total potassium, and 0.97 (95% CI: 0.87, 1.09) for total calcium intake. Pooled RRs for women in the highest compared with the lowest quintiles of a combined mineral diet score were 0.72 (95% CI: 0.65, 0.81) for total stroke, 0.78 (95% CI: 0.66, 0.92) for ischemic stroke, and 0.80 (95% CI: 0.61, 1.04) for hemorrhagic stroke. In the updated meta-analyses of all prospective studies to date, the combined RR of total stroke was 0.87 (95% CI: 0.83, 0.92) for a 100-mg/d increase in magnesium intake, 0.91 (95% CI: 0.88, 0.94) for a 1000-mg/d increase in potassium intake, and 0.98 (95% CI: 0.94, 1.02) for a 300-mg/d increase in calcium intake.

CONCLUSIONS:

A combined mineral diet score was inversely associated with risk of stroke. High intakes of magnesium and potassium but not calcium were also significantly associated with reduced risk of stroke in women.


© 2015 American Society for Nutrition.

Quote

Cold weather does not cause ischemic strokes in patients with atrial fibrillation, he said.

“It’s possible that in cold months, patients are less active and stay inside, which is a risk factor for blood clots,” Guirguis told LifeZette.

Glad the less active, staying inside doesn't apply to me in winter...

True enough George, and getting deep vein thrombus from couch potato syndrome doesn't help :-)